1. Field of the Invention
The present invention relates to a washing machine, and more particularly, to a washing machine control method enabling a resetting of a water re-supply level by determined a water re-supply count for a predetermined time.
2. Discussion of the Related Art
Generally speaking, to perform washing using a washing machine in which laundry has been placed, a wash course is selected to determine a wash pattern, water is supplied to the washing machine according a predetermined water level based on the amount of laundry in the washing machine, and washing is performed based on the predetermined water level. After the water reaches the predetermined level, however, the laundry absorbs a portion of the water, which soon lowers the water level. To compensate for the water level being lowered as above, a washing machine control method according to a related art introduces an additional supply of water before proceeding with the washing step, so that the predetermined water level is maintained. Such a method is illustrated in FIG. 1.
Referring to FIG. 1, the method of the related art achieves the supply of water to a washing machine through the steps of setting water levels W1 and W2 based on an amount and type of laundry in the washing machine, where the water level W1 is the desired water level and the water level W2 is a predetermined reduced level requiring the re-supply of water to avoid damage to the laundry and to achieve a satisfactory washing performance (S101); supplying water to the washing machine according to the water level W1 and a selected wash course (S102); determining whether the level of the water in the washing machine has, due to absorption or other factors, been reduced to the water level W2, i.e., whether the water level has fallen to a substantially lower level that necessitates the supply of additional water (S103); re-supplying the washing machine with a predetermined amount of water, based on the desired water level W1, to raise the water level above the “re-supply” water level W2 (S104); and performing washing using the water of the current level, which is between the levels W1 and W2 defining the extremes of a hysteresis loop, whereupon it is determined that the water is sufficiently absorbed into the laundry and that the water supply step is therefore completed (S105). The water re-supplying step continues until a completion of the water supply, such that washing may proceed. To determine whether to re-supply an amount of water, the water is continuously monitored using a water level sensor, which senses a water pressure of the water in the washing machine.
As described above, at the time of proceeding with the washing step, the level of the water in the washing machine is equal to a level between the initially set water levels W1 and W2, i.e., within a predetermined range. That is, the upper and lower limits of the water level for proceeding the washing step are set before water is supplied to the washing machine, where the upper limit is set as a predetermined maximum assuming no reduction in the water level due to absorption and other factors and the lower limit is set as a predetermined minimum level for proceeding the washing. Meanwhile, an optimal water level for washing varies according to the amount and type of laundry placed in the washing machine, but the amount and type of laundry may result in an excessive degree of absorption.
Therefore, if there is excessive water absorption it may be impossible to reach a satisfactory water level since the water re-supply level W2 is set too low. That is, if, due to a large laundry load and/or very absorbent laundry, the optimal water level is much higher than the water re-supply level W2 as initially set, it is very likely that the water level achieved by the washing machine control method of the related art will be significantly lower than the desired water level. When the water level is too low, washing performance is degraded and the laundry is vulnerable to damage.